Food Allergies in Children

1. Food Allergies in Children Dr C Macaulay Dr C Lemer Dr R Bhatt

2. Background • Food allergy may be confused with food intolerance • Food allergy can be classified into IgE-mediated and non-IgE-mediated reactions. • IgE-mediated reactions are acute and frequently have a rapid onset. • Non-IgE-mediated food allergy is frequently delayed in onset. Most common foods causing allergies • fish • hens' eggs • kiwi fruit • peanuts and tree nuts • sesame • shellfish • soy • wheat.

3. Epidemiology • The prevalence of food allergy in Europe and North America has been reported to range from 6% to 8% in children up to the age of 3 years. • Only 25–40% of self-reported food allergy is confirmed as true clinical food allergy by an oral food challenge

4. Focused history • A personal or family history of atopy is the most significant predictor of allergy. • Ask about history of the reaction • Timing • likely precipitants. • Include history of eczema, asthma, Gastroesophagealreflux • Note that the absence of signs or symptoms does not exclude a food allergy

5. Immediate reactions -IgEmediated • Occur within 2 hours of contact or ingestion • Symptoms are consistent and reproducible and include rashes, itching, wheeze, GI symptoms, angioedema and anaphylaxis • Skin prick tests (or blood tests for specific IgE antibodies to allergens/likely co-­‐allergens) can help diagnosis

6. Treatment in IgE Mediated • Exclusion • Should have dietician advice • Should have an EpiPen if history of anahylaxis or have food allergy and asthma

7. Delayed reactions – Non IgE mediated • Occur > 2hrs after ingestion but within 2-­‐3 days • Often difficult to reproduce and symptoms less specific • May present: • eczema, colic, reflux, loose stools, constipation, food aversion • No tests help diagnosis

8. Treatment Non IgE mediated • Treatment is 2-­‐6 week trial of exclusion of the suspected food followed by reintroduction • If cows milk protein allergy suspected – see GOR guideline

9. When to refer • has had an anaphylactic reaction • had one or more severe delayed reactions • has immediate or delayed allergic reactions to multiple allergens or food groups, especially if there is faltering growth • has had acute allergic reaction with coexisting asthma • moderate – severe eczema where cross reactive or multiple food allergies suspected • has not responded to a single –allergen elimination diet Or: • There is strong clinical suspicion of Ig E-­‐mediated food allergy but allergy test results are negative

10. Top Tips • All children who are excluding multiple foods should be referred to a paediatric dietician • Most cases of urticaria lasting over several days are associated with a viral infection and do not represent a food allergy • Do not use serum-­‐specific IgE testing to diagnose delayed food allergy • Allergy UK : www.allergyuk.org/ has excellent advice sheets for families and clinicians

11. Resources • https://www.nice.org.uk/guidance/cg116 • Cows milk protein allergy: http://cowsmilkallergyguidelines.co.uk/interactive-algorithm/ • https://www.allergyuk.org/childhood-food-allergy/food-allergy-in-babies-and-children